Electrical membrane panels of the type to which the present invention relates include spaced first and second conductive circuits that are formed, such as by printing or vacuum deposition, on separate layers of flexible plastic film. The typical method for producing this type of panel is to form the circuits on individual sheets of plastic film and then join the two sheets of film together, such as by lamination, after the two circuits have been completely formed. This technique can be expensive and entail difficult and time consuming hand lay-up and registration operations, particularly when the plastic films are very thin such as about 1 mil to 5 mils thick. The separate films would be hand registered in stacks and then laminated in a press or autoclave under heat and pressure, but these types of hand operations offer significant potential for problems with dust, dirt, finger prints, kinks and creasing of the films.
The new method which we have developed, as fully described hereinbelow, eliminates all or most of the problems of the foregoing separate sheet method. One of our objectives was to provide a new process that eliminates or reduces hand operations. Another objective was to provide a manufacturing method wherein the membrane panels would be much cleaner, and free from kinks and creases. A further objective was to provide a method for manufacturing electrical membrane panels of flexible plastic films at a reduced cost and without the need for capital equipment such as a press or autoclave for final assembly. These and other objectives of the invention will become apparent from the detailed description which follows.